I figure there are folks on this forum that understand antenna voodoo and can explain something that makes no sense to me. When I started on my slow-build wings, I knew that I wanted ground-based navaids as a backup for satellite navigation and approaches; i.e I wanted to be able to navigate by VOR and make ILS approaches if I had to. Stein was happy to sell me a Bob Archer VOR antenna that fits in the wingtip (pick one) that they said would do VOR navigation and ILS approaches.
Fast forward and I'm now at the stage where it is time to install the antenna. I did a quick internet search and found that VOR frequencies are 108-118 MHz, and the instructions that came with the antenna say it covers that range and more (I think 108-136MHz) so I know it is good for both VOR navigation as well as localizers. However glide slope frequencies are 329-335 MHz which clearly this antenna was not designed to receive.
I called Stein today to ask them about this and they said that if you have a modern navigator, like a GTN650, that it is able to sort out the localizer and glide slope frequencies from this one antenna and that they said other people have been using these same antennas with no complaints.
Can anyone explain this? Is there a misunderstanding between me and Stein? Can anyone here vouch for the fact that they have one of these antennas and can make an ILS approach? i.e. a PRECISION approach?

I have made countless approaches in my RV with said antenna in my left wingtip, works great.